Endovascular treatment of very small (3 mm or smaller) intracranial aneurysms: report of a consecutive series and a meta-analysis

Stroke. 2010 Jan;41(1):116-21. doi: 10.1161/STROKEAHA.109.566356. Epub 2009 Nov 19.

Abstract

Background and purpose: We performed a meta-analysis of published studies on the endovascular treatment of very small intracranial aneurysms, including 71 patients treated at our institution.

Methods: We conducted a computerized MEDLINE search of the literature for reports on the treatment of intracranial aneurysms with a maximum dimension of </=3 mm by using the search terms "small," "tiny," "intracranial aneurysm," "endovascular," and "coil." A total of 7 studies, including our institution's consecutive case series of 71 intracranial aneurysms, were included in this study. We extracted information regarding intraoperative complications, procedural mortality and morbidity, immediate- and long-term angiographic outcomes, and retreatment rate. The meta-analysis was performed with the statistical package Comprehensive Meta-Analysis.

Results: Approximately 61% of the aneurysms in this meta-analysis presented as ruptured, whereas 39% of the aneurysms were unruptured. Procedural rupture rates for very small aneurysms was 8.3% (95% CI, 6.0% to 11.4%). The mortality rate due to procedural rupture was 2.4% (95% CI, 1.2% to 4.7%). The morbidity rate due to thromboembolic complications was 1.9% (95% CI, 0.9% to 3.9%). Subarachnoid hemorrhage within 1 month of treatment occurred in 1.6% (95% CI, 0.6% to 3.7%) of cases. There was no statistically significant difference between unruptured and ruptured aneurysms for any of these outcomes.

Conclusions: Our meta-analysis suggests that treatment of very small aneurysms is feasible and effective in >90% of treated aneurysms. However, the risk of periprocedural rupture is higher than that reported for larger aneurysms. Similarly, the combined rate of periprocedural mortality and morbidity is not negligible (7.3%) and should be considered when considering the best therapeutic option for these aneurysms.

Publication types

  • Comparative Study
  • Meta-Analysis

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Humans
  • Intracranial Aneurysm / diagnosis
  • Intracranial Aneurysm / pathology*
  • Intracranial Aneurysm / therapy*
  • Intraoperative Complications / diagnosis
  • Intraoperative Complications / pathology
  • Intraoperative Complications / prevention & control
  • Male
  • Middle Aged
  • Neurosurgical Procedures / adverse effects
  • Retrospective Studies
  • Treatment Outcome